User's Manual

SPEEDLAN TM
55
IP-Router Setup
Disable ARP-Cache Aging - Use this option if you want to keep a permanant record of the IP to Ethernet
addresses table for each computer directly connected to an interface on the bridge. This feature is helpful when
used in conjuntion with a corporate-wide SNMP monitoring tool to create a database of all Ethernet-to-IP
address combinations on your network. A standard IP router and the bridge will age their ARP cache entries.
It will time out and delete the ARP entries after a certain specified period (usually 10 minutes). The SPEEDLAN
TM has the option of not aging (deleting) any ARP cache entries. This will not normally cause any IP network
problems but could result in a large ARP cache table. Since the typical bridge/router can hold over 10,000
ARP entries this is not normally a problem.
Default TTL - IP hosts on the Internet send out packets with a default “Time To Live” parameter. If you wish
to override the factory default of 64 attempts, you can specify your new default value here.
Preferred IP Address -
From time to time routers will
transmit unsolicited IP packets
such as SNMP Traps, Syslog,
RIP, or IP ARP packets. Most
routers randomly use one of the
IP addresses from one of the
router’s interfaces as the source
IP address for these packets.
On the brouter you can specify the source IP address that you prefer to use for these packets.
Default Router Interface -
This entry should be set to the
interface to which the default
router is connected.
Default Router (IP Ad-
dress)-This entry should be set
to the IP address of the default
router that this SPEEDLAN
TM is to use when it does not
know where to route a particu-
lar IP packet.
IP Routing - IP Routing in the General Setup Menu must be enabled for this menu to appear. This menu must
be completed before saving any configuration in which IP Routing has been enabled. Saving the configura-
tion with incomplete entries in the route table will render the SPEEDLAN TM inoperable.